Operation CHARM: Car repair manuals for everyone.

Idle Speed: Description and Operation

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) controls the Idle Air Control (IAC) valve and regulates the airflow through the idle air bypass passage. The amount of the airflow through the idle air bypass passage determines the idle speed. Engine load regulates the IAC valve. The IAC valve that is not functioning correctly could cause a stalling condition.